“Drink Up,” Michelle Obama’s newest obesity reduction initiative to get children to drink more water, isn’t going down smoothly at all. And I’m not talking about kids hiding their lemonade or stashing their cans of Coke while Mom and Dad turn on the faucet. I’m pointing to a number of anti-Big Food activists who for years have vilified the $200 billion U.S. beverage industry for such practices as selling 64-ounce sodas and clogging landfills with plastic water bottles. This time the activists have complained that the First Lady should have promoted free tap water over bottled water, and water over soda. Some even doubted water’s medical merits. But by trying to take Big Food to the mat, they actually make their ultimate goal harder to achieve: getting 12.5 million obese children and adolescents to shed unhealthy pounds.

In fact, the fastest way to slim down the 17% of American children who are obese requires getting the food and beverage industry fully on board the initiative. Why? Two reasons. First, the industry makes water much more accessible to people who aren’t near public drinking fountains. The number of outlets for bottled water in the U.S. is at least seven times greater than the number of public drinking fountains. And second, persuading kids to drink water requires changing their mindswith marketing campaigns, not just lectures from Mom and Dad. Since they generate about $12 billion in sales on bottled water in the U.S. (according to the International Bottled Water Association), beverage companies can spend hundreds of millions on advertising to get kids to drink water.

But of course the bottled water companies won’t try to get kids to drink water if they’re banned from selling it. To be sure, the anti-beverage industry activists are well-intentioned, and their causes are noble. Yet in hosing the First Lady for her comments, they actually don’t help their cause.

What sparked the water fight? Earlier this month, First Lady Michelle Obama unveiled the new Drink Up initiative at a school in Waterville, Wis. “We all have a choice about what we drink, and when we choose water, we’re choosing to be at our very best,” she said. She urged children to drink “just one more glass” of water a day (not “one more bottle”). Like Obama, the Mayo Clinic also suggests that water be the beverage of choice, and several studies have linked it to weight loss. And of course getting people to drink an extra glass of water can mean they won’t have room to drink and eat higher-calorie drinks and food. So, as a marketer would put it, pushing water is a great way to increase share of stomach.

Perhaps the Drink Up campaign just provided an opportunity for these activists to showcase their own agendas, whether clean and freely available drinking water, healthier beverage choices, or less plastic in landfills. These are all worthy goals, but they lose sight of the bigger picture.

Regardless of their agenda, it’s safe to say that everybody supports efforts to curb childhood obesity. Trashing the beverage industrywhich can mobilize its considerable product development and advertising resources (nearly $1 billion in advertising spent last year by Coke, Pepsi, and Dr. Pepper alone) on behalf of waterwill not move the needle one bit in solving the problem. In fact, excluding the beverage industry from the water business will only worsen obesity, because of the value that bottled water provides: clean water available in so many more locations than there are public water fountains, and ready for transport.

If nudging kids (and their parents) to drink more water is the goal, then water has to be highly accessible, wherever people get thirsty. But there are only 155,000 public water systems in the U.S., fountains that treat, filter, and dispense free tap water, according to the Environmental Protection Agency. That’s fewer than five public fountains for each of the U.S.‘s 35,000 cities and towns. Compare that to the more than 1 million outlets in America that sell bottled water37,000 supermarkets; 180,000 convenience and other food retailers, 28,000 drug stores and 980,000 restaurants.

Beverage companies are the perfect ally because bottled water is profitable for them. Consumption of bottled water grew more than 6% last year, while traditional soda consumption has fallen every year since 1999. Companies that sell bottled water are enjoying healthier operating profit margins. At the

same time, they don’t have a monopoly on consumers’ drinking water options. Families can still get water from a spigot for the dinner table; restaurant patrons can request a free glass of tap water instead of Pellegrino. In fact, a 2012 study by the NPD Group, a market research company, showed that tap water was one of the fastest growing beverages in U.S. restaurants over the past five years, while servings of sodas, coffee, and alcoholic beverages have declined.

Complex societal problems like childhood obesity demand practical, multifaceted solutions, involving both the public and private sectors, and we can’t afford to kick Big Business and its marketing resources out of the tent. Michelle Obama acknowledged this last week at the White House Convening on Food Marketing to Children, when she called for industry to step up its efforts to improve food and beverage nutrition and at the same time requested that the activist community be “constructive and more strategic” in its suggestions.

Purists may not like the fact that somebody might make a buck in helping to solve a public health problem, but that’s how progress is made. Consider that foreign automakers such as Mercedes Benz and Volvo built their reputations and grew their sales with safety features like seat beltspioneered by Volvo engineer Nils Bohlin in 1959more than 30 years before they became mandatory in most U.S. states. Today safety is a key selling point in U.S.-made cars not only because of regulations but also because it is what customers want. And while anti-teen drinking activists might have provided the spark for reduced-alcohol “lite” beers in the 1980s, major breweries have embraced them because consumers want them and they are profitable. Three decades ago four of the top five beers were regular brews; today four of the top five beers are “lite.” Budweiser, the longtime “King of Beers,” has been dethroned by its bantamweight cousin Bud Light.

The anti-industry activists who criticize the details of Obama’s “Drink Up” proposal mean well, but they are the perfect examples of how rigid thinking and mistrust of the other side can derail important societal goals. They need to take a water cooler break and keep their eye on the big picture. Business has to be part of the solution to any vexing public health or societal problem. Attacking companies and threatening their income only slows progress.